It's exactly as described, just a single block, a dirt block in fact, but with something on top, also known as grass, the two blend together quite well, I guess I could just say it's a grass block, you might be wondering why I am overexaggerating this, this is because descriptions require at least 150 characters but I can't say anything about this world other than the fact it is a grass block in the middle of absolutely nothing, and is a useless world, but I can't just put that, meaning I had to write this entire paragraph just explaining why I'm explaining the reason of overexaggerating a single grass block in a world of absolute nothingness.